Useful tips for everyday
What is an example of a systematic error? An error is considered systematic if it consistently changes in the same direction. For example, this could…
What does b1 and b2 mean in regression? Let b1 denote the population coefficient of the intercept and b2 the population coefficient of hh size.…
In what sense are OLS estimates the best among the class of linear unbiased estimators? There is of course one standard result: OLS itself is…
What is the role of eigen vectors in PCA? The eigenvectors and eigenvalues of a covariance (or correlation) matrix represent the “core” of a PCA:…
Is correlation sensitive to outlier? Pearson’s correlation coefficient, r, is very sensitive to outliers, which can have a very large effect on the line of…
What is the formula of mode in probability? If X is a discrete random variable, the mode is the value x (i.e, X = x)…
What are the conditions for applying Chi-square test? Conditions for Applying Chi- square Test: The expected frequency of any item should not be less than…
Can you use R-Squared to compare models? Don’t use R-Squared to compare models This is, as a pretty general rule, an awful idea. In many…
When do you use naive Bayes in R? If all the input features are categorical, Naive Bayes is recommended. However, in case of numeric features,…
What is Elo point spread? (Elo is a closed system where every point gained by one team is a point lost by another.) Normally, any…